Single-chain polypeptides comprising creatine kinase M and creatine kinase B

Abstract

This invention relates to single-chain polypeptides and their genetic sequences comprising creatine kinase M and creatine kinase B. The single-chain polypeptide may be expressed recombinantly. A linker peptide may be interposed between the creatine kinase sequences. A linker peptide of about 6 to about 50 amino acids is preferred. The single-chain polypeptide has utility as a control or calibrator for creatine kinase MB assays, for the purification of creatine kinase antibodies, and as an antigen for the preparation of antibodies.

What is claimed is: 
     
       1. A polynucleotide which codes for an immunostable single-chain polypeptide comprising creatine kinase M joined by a peptide linker sequence to creatine kinase B. 
     
     
       2. A replicable cloning or expression vehicle comprising the polynucleotide of claim 1. 
     
     
       3. The vehicle of claim 2 which is a plasmid. 
     
     
       4. A host cell transformed with a vehicle of claim 2. 
     
     
       5. An E. coli transformed with a replicable cloning or expression vehicle comprising the polynucleotide of claim 1. 
     
     
       6. The polynucleotide of claim 1 identified as (SEQ ID NO:3). 
     
     
       7. A replicable cloning or expression vehicle carrying the sequence set forth in (SEQ ID NO:3). 
     
     
       8. A host cell transformed with the vehicle of claim 7. 
     
     
       9. The host cell of claim 8 which is E. coli. 
     
     
       10. The E. coli of claim 9 which is deposited with the American Type Culture Collection and designated ATCC number 98648. 
     
     
       11. The polynucleotide of claim 1 wherein the linker polynucleotide comprises from about 18 to about 150 nucleotides. 
     
     
       12. An immunostable single chain polypeptide comprising creatine kinase M joined by a peptide linker sequence to creatine kindise B. 
     
     
       13. The polypeptide of claim 12 having an amino acid sequence as set forth in (SEQ ID NO:4). 
     
     
       14. The polypeptide of claim 12 wherein the peptide linker sequence comprises from about 6 to about 50 amino acids.